Thermoplastic Acrylics

drm313mac

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Okay people, it's me, again, and with another question, on a slightly different topic.

For the thermoplastic injection and compression technique, what is the single best (or major favorite) acrylic you prefer? Going through the literature as well as the sales brochures, I am seeing so many choices my head is spinning.
Keystone: Diamond D & Sledgehammer
Merz: Promolux & Promolux High Impact
and zillions more

1. Which, to you, yield the most consistent results?

2. Which have the least structural deformation upon processing? I will assume this is given in terms of feedback from the dentists.

3. Are any of these acrylics teeth specific, meaning, this acrylic works well with X teeth brand but using Y brand the teeth pop out?

4. Which are least or most sensitive to higher temperatures?

5. Which seem to mix easier, more uniformly?

6. Which seem to last the longest, both due to durability as well as resistance to patient damages?

7. Which seem to be the best received by the dentists?

I plan on offering three denture lines, or price points, and I would prefer using the same quality acrylic in all three, though some seem to advocate Lucitone 199 in the economy denture using cold cure. To me, it is the quality of the teeth as well as the time spent that should determine denture quality, meaning, even the cheapest denture should fit well and last a good long time.

What are your thoughts?
 
CloudPeakDL

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I started using L199 but have since swithched to Diamond D. I really like DD. It doesn't have to sit as long before injection and I am very happy with the results.
 
drm313mac

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What is the percent distortion with Diamond D? For example, Lucitone-199 is tested between 5% and 8%, on average 7%. Cheaper acrylic are as high as 11%. On the other end of the spectrum, almost all thermoplastics non-formaldehyde based acrylics are many times lower. I recall reading Ivoclar system (not sure which acrylic they were using) was 0.5%.
Any ideas?

The reason this is so important to me, the less distortion (shrinkage) the less post-delivery adjustments, and the overall happier customers, and then to you the lab techs, the better pay raises.
 
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TECHARTISAN

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Okay people, it's me, again, and with another question, on a slightly different topic.

I plan on offering three denture lines, or price points, and I would prefer using the same quality acrylic in all three, though some seem to advocate Lucitone 199 in the economy denture using cold cure. To me, it is the quality of the teeth as well as the time spent that should determine denture quality, meaning, even the cheapest denture should fit well and last a good long time.

What are your thoughts?

I am interested to know what 3 teeth you have chosen for these 3 price points and why?
 
drm313mac

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TECHARTISAN;

I have not as yet selected the three teeth choices.

Economy: Many here advocate the Image (euro) from Lincoln, though I have not had a response regarding their durability. The same goes for the Heraeus Kulzer Artics. The Uhler teeth I believe are very durable.
I WAS going to go with Dentsply Bioblend IPN, until I heard of Dentsply's business practices.

Mid-grade: I WAS going to go with the Denstply Trubyte IPN teeth, but now must switch to another. I am looking seriously at the Ivoclar Blue, and seek information on durability.

High-end: I WAS planning on the Portrait IPN, as they are fairly esthetic (there are many that are better) and they are very durable. Current top choices are Enigma, Candulor [PhysioStar for anterior, Condylorform NFC for posterior] (Creapearl or Tribos 501 for anterior).

As you can see, I am not decided, yet. All these meet the esthetic requirements for that price range, and the points I am unsure of are the durability of each and the adaptation of each to the acrylic they will go in.

I plan on offering flexibles, but I am not certain if this is just for partials or is an excellent choice for completes as well. The processor will be either the TCS or the CDM Flex Press.
I will offer high-end thermoplastic PMMA, though unsure of the processor. Many say the Ivoclar is the best; I am unsure, and I do not want to be locked into proprietary acrylic.

Suggestions?
 
K

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As for teeth Myerson has a great aconomy tooth (Kenson) mid rang tooth which is the second hardest tooth on the market (DB plus) and there high end is 13 layers hand built, a pretty tooth (myerson specials)
 
araucaria

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As for teeth Myerson has a great aconomy tooth (Kenson) mid rang tooth which is the second hardest tooth on the market (DB plus) and there high end is 13 layers hand built, a pretty tooth (myerson specials)

The Myerson Specials are indeed great teeth, been using them for many years now. They are great for situations where an age-appropriate tooth is required. IMO worth a try.
 
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holly grave digger batman!

I was freaking out....this thread came up...my last post was TODAY???
but I hadnt posted anything today???

then I realized by some strange coincidence...You dug up a post, that my last post in was a YEAR AGO TODAY! LOL
 
AJEL

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David
Rather than worry about the PMMA choice the price difference in most per case is maybe a dollar, I'm not sure why so many will try for the cheapest, its not worth the bother and keeping different PMMA stock on hand is problematic as some have expiration dates. The Diamond D is pretty current technology highly accurate and very durable. Diamond D Heat Cure Powder | Keystone Dental If I remember correctly you are using Ivoclair injection, the cartridge to fit the injector can be obtained from Astron. You could then use the Astron 1180 Astron Dental Corporation - Dentures Vinyl is about as strong as you can get, repairable, & hypoallergenic. With the cartridge from Astron you can then inject Diamond D in the Ivoclair injection (the 1180 is around 3x the cost of DD per case material either would be less than the ivoclair capsuel.). theremo nylon or composites are a different animal, from your past conversations the only one from there would be the Flexite MP, and it is hard to work, requires special equipment, is a little difficult to repair but extremely strong and looks nice. Flexite M.P.
I'm a Vita tooth lab but if I was trying to fake different values I would use Myerson for the cheap denture I use them for nursing home & hospice work now. Myerson :: Kenson Rather than stock many tooth lines I have Vita, Heraeus Basics Heraeus Kulzer - Teeth & some Myerson.
I learned long ago trying to do premium & economy I still put the same care into each and the real difference between a denture mill case and a premium is the care in the product. If you put the same care in each case as you claim, the only real difference will be the cost of the teeth and as you are a DDS it would be less than 1% the price to patient. Make your Jihad to do a good job without false pretensions frills? Strive and make effort and labor to do a right correct rather than false delineations if you are going to put the same labor in each case.
 
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araucaria

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holly grave digger batman!

I was freaking out....this thread came up...my last post was TODAY???
but I hadnt posted anything today???

then I realized by some strange coincidence...You dug up a post, that my last post in was a YEAR AGO TODAY! LOL

Careful, Robin. Both hands on the Bat-rope!
lol, I had a similar experience earlier in the year on a football board, panicked briefly as it appeared somebody else was using my identity - just another date co-incidence

btw, the OP is titled thermoplastics, yet the issue seems to be regular denture base resins and teeth. I was searching 'teeth' and this thread came up in the results.
 
AJEL

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Keith this is from David who seems to like to describe denture PMMA as a thermoformed material, He a DDS I believe read an article about thermoforming PMMA and was investigating it. Most thermoformed we would be using would be nylons or acetals.The only thermoforming PMMA I know of is from Flexite that is approved for extended mucus membranous contact. there is another form but it has some major shrinkage but is used in heart valves and other bio connections, I use that in the clasp covers, only way I stumbled upon it. Are you thinking of crossing the pond in Feb 2013?
 
drm313mac

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Andrew,
As always your advice is excellent, and I thank you.

I am not using the Ivoclar injection and processing system. I decided against it, as it is a thermal system, not thermoplastic. What I went with is the automated tcs system, which heats the cylinders to the proper temperature I set for that specific acrylic, then injects at the push of a button. I then take the flask to the processor, in this case the Mestra M9, which is also sold as the Astron Lab Pro as well as the Nevin 4900 (different facials, same guts). Therefore, I must use the tcs cylinders.

Regarding Diamond-D:
1. After mixing, can I heat to >60 Celsius to drive off the unreacted monomer, prior to loading the cylinder?
OR 2. WITHOUT mixing, can I simply load the acrylic into the cylinder, heat to the melting point of the acrylic (most acrylics are about 160 Celsius),and injest? This then is a physical change, as compared to a chemical reaction.

I am looking into tcs' new full denture acrylic, a hard nylon.

Are there other full denture acrylics I can use as thermoplastic? Besides the known ones such as Flexite MP? Yes, I am looking into the Astron 1180, and ordering some samples we might experiment with.

We will offer 4 denture lines, each marketed to different populations. With ALL 4 I refuse to compromise the fit of the denture, or the acrylic quality. The teeth will range from 2- to 4-layer, the acrylic esthetics will vary as well from say one-shade-fits-all all the way to full characterizations and tinting, from monoplane to multi-degree cusps, etc. From experience I know that what matters most are the fit, the safety, the basic quality, and I refuse to compromise these points.
 
AJEL

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David
TCS good equipment but I would keep a laser thermo meter on hand and use it regularly, I will check with TCS I have no experience with their denture material, sounds interesting. Diamond D was not developed for a preheat system such as a nylon furnace system. Without the heat (or low heat) you could load in the aluminium cartridge & inject the Astron1180 (remember to add the stabilizer to your type III stone) then process in your M9 if it works same as astron processor again I have no experience with the M9, although I know the Astron process and the Nevin quite well, although they have different guts I have both in my little lab.
This sounds just so awkward of a way to process a denture. You loose the advantage of injection when you remove the flask from the machine and place it in the processor. I suppose you would have a pre closed flask and make double use of a nylon (valplast style) flask.
 
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Hey Dave

So its been about a year....good time to touch base and revisit this subject.....

Id wondered if you ever took the plunge into the dark world of alternative dentures.......to answer your questions

1. NO you cant. heating the mixed acrylic and monomer in the tube will do one of two things, likely both, solidify the mass making it beyond the machines ability, and trap and contain unresolved monomer.
2. Maybe you could, but you shouldnt. Loading powder into the cylinder will likely result in scortching and porosity. The particle size is too small for efficient thermal dispersion the air between particles acts, to a degree, as insulation. That air will also incorporate into any melted material you sucessfully extrude. I know bead loaded cartridges have air entrapped as well but the reduced particle surface area of the larger beads vs powder particles makes all the difference in the world.
3...okay not answering a question here but "I am looking into tcs' new full denture acrylic, a hard nylon.", makes no sense. Its either nylon or acrylic, "I am looking into tcs' new full denture BASE, a hard nylon." <is what I assume you mean? I am unfamiliar with the product so cannot weigh in but your statement is circular.

Your options include Bre-Crystal, Perflex Acry free, and flexite mp as far as I know. If I was pursuing this and none of these companies products was exactly what I was looking for.....Id contact them, explain what isnt right and ask them for a minimum order requirement for a custom blend. Because otherwise....
If you were to buy Diamond D in bulk, cast it into pellets, vacuum age the pellets...then get ADA approval to use them, which will probably require licensure fees and possibly FDA facilities licensing as you will be manufacturing a medical material. All of this shouldnt run you more then 1/4mill. lol

As thermoplastic PMMA injection does not require it, I am curious, are you just using the Mestra for controlling prolonged cooldown to reduce material crystalization? If so how has that worked out for you?

Sorry if this sounds prickish to any readers but unless you understand the difference between a themally cured acrylic and a thermoplastic acrylic please read this post of mine, and this article, specifically, the thermoplastic acrylic section, before commenting. They are different beasts.
 
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X

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This sounds just so awkward of a way to process a denture. You loose the advantage of injection when you remove the flask from the machine and place it in the processor. I suppose you would have a pre closed flask and make double use of a nylon (valplast style) flask.

Yea does to me aswell, if he's planning on injecting acrylic resin in the tcs unit then transferring it to a processing unit to cure the acrylic isn't he going to run into some trouble with the acrylic no longer being under pressure during curing??? Shrinkage and porosity?

Also he mentions fit being the most important factor. I've done several nylon injected dentures in cases when I've really wanted something strong. IMO I would have a really hard time saying an injected nylon denture would have a better fit then any acrylic resin denture injected or press packed. To me the nylon just does not adapt to the model as well.

I'd be interested in your thoughts on this AJ as well as others.
 
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I cannot speak to nylon as I have already raised question of this....I wouldnt use a nylon material personally as it is EVEN MORE hydrophillic than the thermal cure acrylics most of us use, so while it might help with monomer sensitivity it is no other way an improvement IMHO.

Previous conversations with Dave in this regard have always focused on PMMA. In thermoplastic injection the material does not need to cure. Its already cured. This improves the materials dimensional stability and limits variation to the thermal coefficient of expansion of the acrylic, which should in an ideal world be matched closely to your investment and model material. The critical issues of fit happen during phase change, in the first 45 sec to 2 minutes, after this the material has already passed its glass transition, continued pressure is unnecessary and wasteful.

These materials are often quick cooled allowing injection and devest in about 5 minutes. HOWEVER, Quick cooling can reduce impact resistance and if cooled waaay to quickly warpage that will damage fit.

Manufacturers usually state in their directions that material and fit benefit from progressive cooling overnight. This prevents crystal formation within the amorphous polymer matrix. Crystalization creates weaknesses in the lattice that become initiation points in impact related fracture. I suspect, This slow cool is what Dave is using the polymerization unit for.....temperature controlled cooling.
 
AJEL

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The processing is one phase, press pack done properly is great, injection of a Heat PMMA, and the new ivocap seems to be injection of a self cure with heated flasks. Each system has been tested for a specific material keep to the FDA approved material per system. A good technician can do a good job. Accuracy, is important to the patient, and starts with a great impression.
I took part in a study in 1970, we didn't have all the impression materials we do now. We stayed with 2: ZOE & rubber base in custom trays from Lang. 10 Impressions were taken of each patient (10 patients in all 5 men 5 women),at different times at different hydration & in different temperature rooms. within the same impression material under different situations we found 10 impressions processed lucitone baseplates and 3 of 10 would interchange (but not perfect-ally).
My thought is we should do the best with the highest quality material, master it and a patient will come in that no matter how hard you try things might not work.
If Dave is trying to make non allergic dentures he may be incurring a Cliford charge on each patient, as the impression material, sterilization technique or denture materials can sensitize a patient. A Clifford institute report per patient will list everything down to the brand & lot of cotton swab that could possibly cause problem. Walter the chemist there told me Vinyl showed up with the smallest reactions, but people are people and even Vinyl will have someone sensitive eventually. Walter had even seen a few people sensitive to porclean teeth.

James I have done some nylon dentures probably for the same reason as you did, the fit is ok but then they broke off the teeth and that was difficult to repair. And reline is out of the question. Acetal dentures even with proper expansion stone never really fit quite right, altough I have a few all on 4 with acetal going right now, holding my breath on those.
 
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droberts

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Andrew,
As always your advice is excellent, and I thank you.

I am not using the Ivoclar injection and processing system. I decided against it, as it is a thermal system, not thermoplastic. What I went with is the automated tcs system, which heats the cylinders to the proper temperature I set for that specific acrylic, then injects at the push of a button. I then take the flask to the processor, in this case the Mestra M9, which is also sold as the Astron Lab Pro as well as the Nevin 4900 (different facials, same guts). Therefore, I must use the tcs cylinders.

Regarding Diamond-D:
1. After mixing, can I heat to >60 Celsius to drive off the unreacted monomer, prior to loading the cylinder?
OR 2. WITHOUT mixing, can I simply load the acrylic into the cylinder, heat to the melting point of the acrylic (most acrylics are about 160 Celsius),and injest? This then is a physical change, as compared to a chemical reaction.

I am looking into tcs' new full denture acrylic, a hard nylon.

Are there other full denture acrylics I can use as thermoplastic? Besides the known ones such as Flexite MP? Yes, I am looking into the Astron 1180, and ordering some samples we might experiment with.

We will offer 4 denture lines, each marketed to different populations. With ALL 4 I refuse to compromise the fit of the denture, or the acrylic quality. The teeth will range from 2- to 4-layer, the acrylic esthetics will vary as well from say one-shade-fits-all all the way to full characterizations and tinting, from monoplane to multi-degree cusps, etc. From experience I know that what matters most are the fit, the safety, the basic quality, and I refuse to compromise these points.

Each system comes with instructions, was design and tested for their own purpose. I would not recommend mixing.
Your providing a service to your patient, please don't use them as a guinea pig.
 
nvarras

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Each system comes with instructions, was design and tested for their own purpose. I would not recommend mixing.
Your providing a service to your patient, please don't use them as a guinea pig.

I agree....why try to reinvent the wheel at the expense of the patient.
 

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